Abstract

Eddy Ardonne (Nordita)


What constitutes a topological phase? A case study

Topological phases of matter have attracted much attention in recent years. In this talk, the question what is required of a phase before it can be called topological will be addressed. We will approach this problem by studying two `states' which are not topological, and discuss why they are not. We will point out a relation between these two states, the so-called Haffnian and Haldane-Rezayi states. We argue that the `irrationality' of the former is replaced by the `non-unitarity' of the latter, making it, in some sense, better behaved. All of these concepts will be introduced in this black-board talk, no prior knowledge will be required.